Glutamatergic neuronal activity regulates angiogenesis and blood-retinal barrier maturation via Norrin/β-catenin signaling

Interactions among neuronal, glial, and vascular components are crucial for retinal angiogenesis and blood-retinal barrier (BRB) maturation. Although synaptic dysfunction precedes vascular abnormalities in many retinal pathologies, how neuronal activity, specifically glutamatergic activity, regulates retinal angiogenesis and BRB maturation remains unclear. Using in vivo genetic studies in mice, single-cell RNA sequencing (scRNA-seq), and functional validation, we show that deep plexus angiogenesis and paracellular BRB maturation are delayed in Vglut1-/- retinas where neurons fail to release glutamate. By contrast, deep plexus angiogenesis and paracellular BRB maturation are accelerated in Gnat1-/- retinas, where constitutively depolarized rods release excessive glutamate. Norrin expression and endothelial Norrin/β-catenin signaling are downregulated in Vglut1-/- retinas and upregulated in Gnat1-/- retinas. Pharmacological activation of endothelial Norrin/β-catenin signaling in Vglut1-/- retinas rescues defects in deep plexus angiogenesis and paracellular BRB maturation. Our findings demonstrate that glutamatergic neuronal activity regulates retinal angiogenesis and BRB maturation by modulating endothelial Norrin/β-catenin signaling.

The impact of cancer metastases on COVID-19 outcomes: A COVID-19 and Cancer Consortium registry-based retrospective cohort study

BACKGROUND

COVID-19 can have a particularly detrimental effect on patients with cancer, but no studies to date have examined if the presence, or site, of metastatic cancer is related to COVID-19 outcomes.

METHODS

Using the COVID-19 and Cancer Consortium (CCC19) registry, the authors identified 10,065 patients with COVID-19 and cancer (2325 with and 7740 without metastasis at the time of COVID-19 diagnosis). The primary ordinal outcome was COVID-19 severity: not hospitalized, hospitalized but did not receive supplemental O2 , hospitalized and received supplemental O2 , admitted to an intensive care unit, received mechanical ventilation, or died from any cause. The authors used ordinal logistic regression models to compare COVID-19 severity by presence and specific site of metastatic cancer. They used logistic regression models to assess 30-day all-cause mortality.

RESULTS

Compared to patients without metastasis, patients with metastases have increased hospitalization rates (59% vs. 49%) and higher 30 day mortality (18% vs. 9%). Patients with metastasis to bone, lung, liver, lymph nodes, and brain have significantly higher COVID-19 severity (adjusted odds ratios [ORs], 1.38, 1.59, 1.38, 1.00, and 2.21) compared to patients without metastases at those sites. Patients with metastasis to the lung have significantly higher odds of 30-day mortality (adjusted OR, 1.53; 95% confidence interval, 1.17-2.00) when adjusting for COVID-19 severity.

CONCLUSIONS

Patients with metastatic cancer, especially with metastasis to the brain, are more likely to have severe outcomes after COVID-19 whereas patients with metastasis to the lung, compared to patients with cancer metastasis to other sites, have the highest 30-day mortality after COVID-19.

Oral antivirals for COVID-19 among patients with cancer

Purpose

Immunocompromised individuals, such as those diagnosed with cancer, are at a significantly higher risk for severe illness and mortality when infected with SARS-CoV-2 (COVID-19) than the general population. Two oral antiviral treatments are approved for COVID-19: Paxlovid® (nirmatrelvir/ritonavir) and Lagevrio® (molnupiravir). There is a paucity of data regarding the benefit from these antivirals among immunocompromised patients with cancer, and recent studies have questioned their efficacy among vaccinated patients, even those with risk factors for severe COVID-19.

Methods

We evaluated the efficacy and safety of nirmatrelvir/ritonavir and molnupiravir in preventing severe illness and death using our database of 457 patients with cancer and COVID-19 from Brown University-affiliated hospitals. 67 patients received nirmatrelvir/ritonavir or molnupiravir and were compared to 56 concurrent controls who received no antiviral treatment despite being eligible to receive it.

Results

Administration of nirmatrelvir/ritonavir or molnupiravir was associated with improved survival and lower 90-day all-cause and COVID-19-attributed mortality (p<0.05) and with lower peak O2 requirements (ordinal odds ratio [OR] 1.52, 95% confidence interval [CI] 0.92-2.56).

Conclusion

Acknowledging the small size of our sample as a limitation, we concluded that early antiviral treatment might be beneficial to immunocompromised individuals, particularly those with cancer, when infected with SARS-CoV-2. Larger-scale, well-stratified studies are needed in this patient population.

Glutamatergic neuronal activity regulates angiogenesis and blood-retinal barrier maturation via Norrin/β-catenin signaling

Interactions among neuronal, glial and vascular components are crucial for retinal angiogenesis and blood-retinal barrier (BRB) maturation. Although synaptic dysfunction precedes vascular abnormalities in many retinal pathologies, how neuronal activity, specifically glutamatergic activity, regulates retinal angiogenesis and BRB maturation remains unclear. Using in vivo genetic studies in mice, single-cell RNA-sequencing and functional validation, we show that deep plexus angiogenesis and paracellular BRB maturation are delayed in Vglut1 -/- retinas where neurons fail to release glutamate. In contrast, deep plexus angiogenesis and paracellular BRB maturation are accelerated in Gnat1 -/- retinas where constitutively depolarized rods release excessive glutamate. Norrin expression and endothelial Norrin/β-catenin signaling are downregulated in Vglut1 -/- retinas, and upregulated in Gnat1 -/- retinas. Pharmacological activation of endothelial Norrin/β-catenin signaling in Vglut1 -/- retinas rescued defects in deep plexus angiogenesis and paracellular BRB maturation. Our findings demonstrate that glutamatergic neuronal activity regulates retinal angiogenesis and BRB maturation by modulating endothelial Norrin/β-catenin signaling.

Outpatient anti-spike monoclonal antibody administration is associated with decreased morbidity and mortality among patients with cancer and COVID-19

Patients with cancer have many comorbidities that increase their risk of death from Coronavirus disease 2019 (COVID-19). Anti-spike monoclonal antibodies (mAbs) reduce the risk of hospitalization or death from COVID-19 in the general population. To our knowledge, no studies have focused on the clinical efficacy of mAbs compared to no outpatient treatment exclusively among patients with solid tumors and hematologic malignancies, who are often excluded from clinical trials. We studied patients with cancer who had COVID-19 between 11.9.2020 and 7.21.2022 and received mAbs in an outpatient setting. We compared hospitalization and mortality rates to those of patients with cancer concurrently diagnosed with COVID-19, who were eligible for mAbs, but did not receive any outpatient treatment. 63 patients received mAbs and 89 no outpatient treatment. Administration of mAbs was associated with lower 90-day hospitalization (20.6% vs. 60.7%, p <0.001), all-cause (6.3% vs. 19.1%, p 0.025) and COVID-19-attributed (3.2% vs. 14.6%, p 0.019) mortality rates, and lower peak O2 requirements (ordinal Odds Ratio [OR] = 0.33, 95% Confidence Intervals [CI] = 0.20-0.53). Administration of mAbs (aHR 0.21, p <0.001), age (≥ 60 years, adjusted Hazard Ratio [aHR] 1.86, p=0.033), and metastases (aHR 0.41, p 0.007) were independently associated with hospitalization. mAb treatment remained significantly associated with all-cause (aHR 0.27, p 0.019) and COVID-19-attributed (aHR 0.19, p 0.031) mortality, after adjustment for other factors. mAb administration was associated with improved clinical outcomes among vulnerable patients with cancer and COVID-19. With no mAbs approved currently for treatment against the prevalent circulating variants, the development of new mAbs should be a research priority.

Distinct Th17 effector cytokines differentially promote microglial and blood-brain barrier inflammatory responses during post-infectious encephalitis

Group A Streptococcus (GAS) infections can cause neuropsychiatric sequelae in children due to post-infectious encephalitis. Multiple GAS infections induce migration of Th17 lymphocytes from the nose into the brain, which are critical for microglial activation, blood-brain barrier (BBB) and neural circuit impairment in a mouse disease model. How endothelial cells (ECs) and microglia respond to GAS infections, and which Th17-derived cytokines are essential for these responses are unknown. Using single-cell RNA sequencing and spatial transcriptomics, we found that ECs downregulate BBB genes and microglia upregulate interferon-response, chemokine and antigen-presentation genes after GAS infections. Several microglial-derived chemokines were elevated in patient sera. Administration of a neutralizing antibody against interleukin-17A (IL-17A), but not ablation of granulocyte-macrophage colony-stimulating factor (GM-CSF) in T cells, partially rescued BBB dysfunction and microglial expression of chemokine genes. Thus, IL-17A is critical for neuropsychiatric sequelae of GAS infections and may be targeted to treat these disorders.

Outpatient anti-spike monoclonal antibody administration is associated with decreased morbidity and mortality among patients with cancer and COVID-19

BACKGROUND

Patients with cancer have many comorbidities that increase their risk of death from Coronavirus disease 2019 (COVID-19). Anti-spike monoclonal antibodies (mAbs) reduce the risk of hospitalization or death from COVID-19 in the general population. To our knowledge, no studies have focused on the clinical efficacy of mAbs compared to no outpatient treatment exclusively among patients with solid tumors and hematologic malignancies, who are often excluded from clinical trials.

METHODS

We studied patients with cancer who had COVID-19 between 11.9.2020 and 7.21.2022 and received mAbs in an outpatient setting. We compared hospitalization and mortality rates to those of patients with cancer concurrently diagnosed with COVID-19, who were eligible for mAbs, but did not receive any outpatient treatment.

RESULTS

63 patients received mAbs and 89 no outpatient treatment. Administration of mAbs was associated with lower 90-day hospitalization (20.6% vs. 60.7%, p<0.001), all-cause (6.3% vs. 19.1%, p=0.025) and COVID-19-attributed (3.2% vs. 14.6%, p=0.019) mortality rates, and lower peak O2 requirements (ordinal Odds Ratio [OR]=0.33, 95%Confidence Intervals [CI]=0.20-0.53). Administration of mAbs (aHR 0.21, p<0.001), age (≥ 60 years, adjusted Hazard Ratio [aHR] 1.86, p=0.033), and metastases (aHR 0.41, p=0.007) were independently associated with hospitalization. mAb treatment remained significantly associated with all-cause (aHR 0.27, p=0.019) and COVID-19-attributed (aHR 0.19, p=0.031) mortality, after adjustment for other factors.

CONCLUSIONS

mAb administration was associated with improved clinical outcomes among vulnerable patients with cancer and COVID-19. With no mAbs approved currently for treatment against the prevalent circulating variants, the development of new mAbs should be a research priority.

Interplay of Immunosuppression and Immunotherapy Among Patients With Cancer and COVID-19

Importance

Cytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.

Objective

To determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.

Design, Setting, and Participants

This registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.

Exposures

Immunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).

Main Outcomes and Measures

The primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.

Results

The median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).

Conclusions and Relevance

This cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.

Trial Registration

ClinicalTrials.gov Identifier: NCT04354701.

mRNA vaccination decreases COVID-19-associated morbidity and mortality among organ transplant recipients: a contemporary cohort study

Background

Organ transplant recipients (OTRs) are less protected from vaccination than immunocompetent hosts. Additional vaccine doses have shown increased immunogenicity. Few studies have assessed their clinical efficacy, particularly against Omicron variants, as most included patients from earlier phases of the pandemic, with higher base mortality rates.

Methods

We studied adult OTRs who had coronavirus disease 2019 (COVID-19) between 12/15/21 and 5/25/22. We compared clinical outcomes between those who had received 2 or ≥3 doses of an mRNA vaccine and concurrent unvaccinated controls.

Results

Among 103 OTRs, vaccination was associated with lower 90-day mortality (unvaccinated vs 2 vs ≥3 doses: 25% vs 7% vs 3%; P = .003), hospital (unvaccinated vs 2 vs ≥3 doses: 56% vs 37% vs 27%; P = .018) and intensive care unit (ICU; unvaccinated vs 2 vs ≥3 doses: 25% vs 15% vs 3%; P = .001) admission rates, and peak O₂ requirements (ordinal scale Kendall’s tau b = –0.309 [lower scores, ie, O₂ requirements with more vaccine doses]; P = .003). Age (age >60 years: adjusted hazard ratio [aHR], 7.73; P = .016; administration of antispike monoclonal antibody: aHR, 0.17; P = .042) and vaccination, especially with ≥3 doses (aHR, 0.105; P = .01), were independently associated with 90-day mortality. Black (P = .021) and Hispanic (P = .016) OTRs were underrepresented among the vaccinated, especially in the ≥3-dose group.

Conclusions

Despite lower mRNA vaccine efficacy in OTRs and against Omicron variants, vaccination protects this vulnerable patient population from severe COVID-19 and death. Ethnic and racial disparities in health care have been exacerbated by the COVID-19 pandemic and warrant better community outreach efforts.

Mural Wnt/β-catenin signaling regulates Lama2 expression to promote neurovascular unit maturation

Neurovascular unit and barrier maturation rely on vascular basement membrane (vBM) composition. Laminins, a major vBM component, are crucial for these processes, yet the signaling pathway(s) that regulate their expression remain unknown. Here, we show that mural cells have active Wnt/β-catenin signaling during central nervous system development in mice. Bulk RNA sequencing and validation using postnatal day 10 and 14 wild-type versus adenomatosis polyposis coli downregulated 1 (Apcdd1-/-) mouse retinas revealed that Lama2 mRNA and protein levels are increased in mutant vasculature with higher Wnt/β-catenin signaling. Mural cells are the main source of Lama2, and Wnt/β-catenin activation induces Lama2 expression in mural cells in vitro. Markers of mature astrocytes, including aquaporin 4 (a water channel in astrocyte endfeet) and integrin-α6 (a laminin receptor), are upregulated in Apcdd1-/- retinas with higher Lama2 vBM deposition. Thus, the Wnt/β-catenin pathway regulates Lama2 expression in mural cells to promote neurovascular unit and barrier maturation.

Timing and degree of left atrial stunning and reverse functional remodeling following electrical cardioversion in patients with recent onset atrial fibrillation

Background

Atrial fibrillation (AF) results in left atrial electrical, structural and functional remodeling. Restoration of sinus rhythm hallmarks the beginning of reverse remodeling, the extent of which may depend on the type of AF.

Purpose

The aim of the study was to assess resumption of left atrial function after electric cardioversion in patients with recent onset AF and to explore the association between reverse remodeling and the type of atrial fibrillation.

Methods

Patients with AF duration &lt;48 hours were prospectively included. Trans-thoracic echocardiography was performed prior, immediately after (2–4 hours) and 7–10 days following CV. Left atrial volume index (LAVI), left atrial global longitudinal strain during reservoir (LAGLS-res), conduit (LAGLS-cond) and contractile (LAGLS-contr) phases, left atrial ejection fraction (LAEF) and left ventricular ejection fraction (LVEF) were measured.

Results

Forty-three patients (84% males) aged 55±9.6 years, (mean±SD), with median CHA2DS2-VASc score 1 (interquartile range 0–1) were included. Repeated measure analysis of variance revealed a statistically significant overall change for LAGLS-res F(2,78)=55.4, p&lt;0,001, LAGLS-cond F(2,78)=23.3, p&lt;0,001, LAGLS-contr F(2,78)=39.7, p&lt;0,001, LAEF F(2,80)=28.5, p&lt;0.001 and LVEF F(2,80)=8.4, p&lt;0.001. At 7–10 days, LAGLS-contr 12±4%, LAEF 53±9% and LVEF 60±6 (mean±SD) return within normal reference intervals. Notably left atrial recovery seems to precede left ventricular recovery. No statistical significant interaction with the type of atrial fibrillation could be shown.

Conclusion

Left atrial functional reverse remodeling occurs within ten days after successful electric cardioversion of patients with recent onset atrial fibrillation.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Swedish Heart-Lung Foundation, Correvio International Sárl (Geneva Switzerland), Selanders Stiftelse

Activation of inflammatory/coagulation system following electrical cardioversion of patient with recent onset atrial fibrillation: an explorative study of the relation to white matter hyperintensities

Background

White matter hyperintensities (WMH), assessed using Fazekas scale, are more prevalent in patients with atrial fibrillation (AF), although its pathophysiologic mechanism(s) is unclear.

Purpose

The study objective was to explore the association between cardiac, inflammatory and coagulation biomarkers and white matter hyperintensities in anticoagulant-naïve patients following electrical cardioversion (CV) of recent onset AF.

Methods

Patients with AF duration &lt;48 hours were prospectively included. Brain magnetic resonance imaging (MRI), C-reactive protein (CRP), high-sensitivity troponin T (hs-TNT), NT-proBNP, Interleukin 6, P-selectin, D-dimer, prothrombin fragment 1+2, von Willebrand factor Ag, coagulation factor VIII C and fibrinogen, were obtained sequentially prior, after (2–4 hours) and 7–10 days following CV. Repeated measure analysis of variance was performed.

Results

Forty-three patients (84% males), aged 55±9.6 years, (mean±SD) with median CHA2DS2-VASc score 1 (interquartile range 0–1) were included. Sequential MRI showed no new brain lesions after CV, while WMH were present at baseline in 21/43 (49%) patients. Repeated measure analysis of variance revealed a statistically significant overall change for hs-TNT: F(2,84)=6.056, p=0.03, NT-proBNP: F(2,84)=106.02, p&lt;0.001, P-selectin: F(2,84)=8.69, p&lt;0.001 and vWF:Ag: F(2,84)=4.078, p=0.02. CRP, IL-6, coagulation factor VIII-C and fibrinogen showed the same pattern, however none reached statistical significance. Patients with WMH had persistent higher values for CRP, hs-TNT, D-dimer, prothrombin fragment 1+2 and fibrinogen prior and after CV, as values at 7–10 days coincided; however, statistical interaction was not significant.

Conclusion

Transient activation of inflammatory and coagulation systems during atrial fibrillation subsides within 7–10 days after electric cardioversion of recent onset atrial fibrillation. A tendency of higher degree of activation during atrial fibrillation was observed in patients with white matter hyperintensities.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Swedish Heart-Lung Foundation, Swedish Research Council, Correvio International Sárl (Geneva Switzerland), Selanders Stiftelse

P1080Magnetic resonance imaging after electrical cardioversion of recent-onset atrial fibrillation in anticoagulant-naive patients - a study exploring clinically silent cerebral lesions

Funding Acknowledgements

Unrestricted grants from the Swedish Heart-Lung Foundation, the Swedish Research Council, Correvio International Sárl (CH) and Selanders stiftelse

Background

Patients with atrial fibrillation (AF) have a high incidence of cognitive impairment, which may be related to clinically silent microembolism causing cerebral infarctions.

Purpose

To explore the occurrence and timing of silent brain lesions following electrical cardioversion (CV) of recent onset AF in anticoagulant-naïve patients and to further study related effects on cognitive function and biomarkers of cerebral damage, S100b.

Methods

Patients with AF duration &lt; 48 hours were prospectively included. Brain magnetic resonance imaging (MRI) and S100b, were obtained prior, after and 7-10 days following CV. Trail making tests (TMT-A and TMT-B) and their difference, ΔΤΜΤ, were assessed prior to CV, 7-10 days and 30 days after CV.

Results

Forty-three patients (84% males) with mean CHA2DS2-VASc score 0.6 ± 0.7 were included. Sequential MRI, including diffusion weighted scans, showed no new brain lesions after CV.

Chronic white matter hyperintensities (WMH) were present at baseline in 21/43 (49%) patients. By partitioning the study population into four major groups according to the extend of WMH (Fazekas score 0 or ≥ 1) and the presence or absence of TE risk factors (CHA2DS2-VASc score 0 or ≥ 1), the TE risk as defined by CHA2DS2-VASc score ≥ 1, was associated with a higher incidence of WMH, Pearson χ2(1,N = 43)=3.95, p = 0.047.

The S100b (µg/l) levels increased significantly from baseline, (mean ± SD) 0.0472 ± 0.0182 to 0.0551 ± 0.0185 after CV, p = 0.001 and then decreased 7-10 days after CV to 0.0450 ± 0.0186, p &lt; 0.001. Subgroup analysis according to the presence of at least one TE risk factor as defined by CHA2DS2-VASc score showed that statistical significance of repeated measures ANOVA was maintained; for patients with no risk factors F (2,30)=12.59, p &lt; 0.001 and for patients with CHA2DS2-VASc score ≥1 F(2,36)=4.43, p &lt; 0.019.

Consecutive TMT scores improved successively after CV, being statistically and clinically significant for TMT-B (p &lt; 0.01) and ΔΤΜΤ (p = 0.005) between 7-10 days and 30 days after CV (Reliable Change Index &gt;1.96).

Conclusion

New brain lesions could not be detected on MRI after CV, but the high incidence of white matter hyperintensities and the transient increase in S100b may indicate transient or minor brain damage undetectable by MRI thus heightening the need to reevaluate thromboembolic risk prior to CV even in low risk patients.

Abstract Figure. S100b_TMT

Secondary orbital implant insertion in an anophthalmic patient after orbital reconstruction

The authors report the case of a 20-year-old man who underwent enucleation of his right eye with teratoma when he was an infant, without volume replacement by an implant. As a result, an underdeveloped shallow bony orbit finally occurred. Also, a contracted socket was present with shallow lower fornix, making ophthalmic prosthesis fitting almost impossible. The patient underwent surgical reconstruction of the orbit with expansion of the orbit vertically and horizontally. A secondary implant with an adequate volume was inserted to correct the orbital volume deficit. The previous expansion of the orbit allowed the insertion of an 18 mm-diameter hydroxyapatite implant wrapped in fascia lata. The lower fornix was expanded with a mucosal graft in order to overcome the socket contraction and the conjunctival shortage. The authors conclude that the final result of this approach is satisfactory. Almost 20 years after enucleation of an eye with teratoma, an attempt was made to correct most of the difficult problems dealing with a malformed shallow orbit and a contracted socket. The young patient is now able to wear a fine ophthalmic prosthesis and his appearance is greatly improved.

An ecological model for school-based mental health services for urban low-income aggressive children

An ecological model for school-based mental health services that targets urban low-income aggressive children--a highly vulnerable and underserved population--is presented. The goals of the model are to increase children's and teachers' involvement in the delivery of services and to increase the integration of these services into existing school resources and activities. The model proposes that mental health service providers work in collaboration with teachers to deliver services that (1) can be managed by existing school resources and personnel, (2) are related to empirically based factors associated with reduced aggression and increased social functioning, and (3) are group administered to increase the number of children served and to reduce stigmatization associated with mental health services. The model is individualized and flexible by acknowledging that contexts for aggression differ across classrooms and children and by providing services specific to those contexts. Two studies are presented illustrating the application of this model to decrease aggression and increase academic engagement in low-income urban public schools.

Effect of posterior fixation sutures on the accommodative element of partially accommodative strabismus

In a prospective study, we investigated the effect of posterior fixation sutures on the accommodative element of partially accommodative strabismus. Twenty patients were included in the study. Recession of one or both medial rectus muscles combined with bilateral posterior fixation sutures was performed on each patient. The results showed that this combined operation had a greater effect on the angle without glasses at both distance and near fixation, but not enough to eliminate the angle without glasses in all the cases. The results in patients with convergence excess are not satisfactory, as far as the reduction of the angle without glasses is concerned. In patients without convergence excess, this operation is effective in satisfactorily reducing the squint without glasses when the difference of the angle with and without glasses does not exceed 15 delta.